Behavior and survival of hatchery reared advanced fingerling largemouth bass using radio telemetry Brandon Thompson
Florida largemouth bass Micropterus salmoides floridanus Premier freshwater sportfish 60% of all angler days 1.3 billion dollars
10 Lake Griffin EF L/F 2007 Percent frequency 8 6 4 2 0 Age 1 bass 1 6 11 16 21 26 31 36 41 46 51 56 61 Length (1-cm)
10 Lake Griffin EF L/F 2007 Percent frequency 8 6 4 2 0 Age 1 bass 1 6 11 16 21 26 31 36 41 46 51 56 61 Length (1-cm) Percent frequency 10 8 6 4 2 Age -1 bass Healthy Recruitment L/F 0 1 6 11 16 21 26 31 36 41 46 51 56 61 Length (1-cm)
Florida Bass Conservation Center Completed February 2007 39,000 SF Production Bldg High production capabilities 1.5 million fingerlings 1 million advanced fingerlings
Fingerlings New systems, fish kills, renovations Stocking Advanced fingerlings Supplemental stocking Augment natural recruitment Recruitment limited systems Can produce high contribution Lake Talquin (live reared)
Advanced Fingerling Larger size (~ 4 inch) Traditional fingerlings; 1-2 inch Raised on pellets (high production) Higher survival Piscivorous New Culture techniques Improved artificial feed Release techniques Transition to live prey Out of season spawning
Stock Enhancement Project Ocklawaha chain selected as research system Stock Lake Griffin for 3 years and track contribution Stock Lake Carlton as research lake for radio telemetry
Why use radio telemetry? We know very little what stocked fish do after release Behavior Survival Movement and dispersal Habitat use
Radio Tag Selection ATS model A2414 (0.24 g) - 2% rule Expected battery life 30 d Range, accuracy, detection Smallest transmitters ever used in a fisheries study!
Surgical Techniques Smallest fish tagged in a study Adopted from USGS Shielded needle technique Specialized tools Fish seemed to recover well from surgery Entry hole for transmitter Exit hole for antenna
Tag Effect Studies Radio tagging small bass/hatchery bass Affects unknown from tagging Assumptions of Telemetry Tagged fish represent untagged Growth and predator avoidance Similar to untagged
Telemetry Site: Lake Carlton 400 acre lake on 76,000 acre chain Representative habitat Habitat mapping ArcMap Vegetation polygons Fish locations overlay Movement analysis Habitat analysis Bulrush
2009 (May 18) Tagging - 50 hatchery fish tagged Stocking Stocked ~ 11,000 hatchery fish along with tagged fish both years 2010 (March 30) - 30 Hatchery bass - 20 Wild bass Focus on 2010 comparison
Tracking Methods Tracked all fish daily Stationary receiver in canal Fish located and data recorded Locations with GPS Depth, vegetation, environmental
Survival and Predators
Results - Survival Confirmed fish deaths: 16 Hatchery 14 (Predation; fish and birds) Wild 2 (tagging mortalities) 14 and 30 Day Survival Wild had significantly higher survival 62% 90% 82% 38%
Normal hatchery fish movement? Single fish locations through 14 days
High Movement Fish Fish #14
Movement Dispersal > 5/30 (17%) of hatchery fish left Lake Carlton (0 wild fish) Movements Range: 6-9581 (6 miles!) Record movement (24 hrs) = 1.8 miles 700 Dispersal 100 Movement Per Day 600 90 80 500 70 Meters 400 300 200 401 566 Hatchery 21-day Wild 21-day Meters 60 50 40 74.5 Hatchery Wild 100 272 153 184 347 30 20 0 7-day 14-day 21-day 10 25.7 0
All fish locations - 2009
Fish # 38 Offshore Hatchery Fish
Habitat Selection - GIS 50.00 40.00 Proportion of locations used 30.00 20.00 10.00 - Offshore Submersed Grasses Bulrush Cattail 2010 Hatchery 2010 Wild
Growth 0.6 Growth - mm/day 2.5 Growth - % body weight 0.5 2.0 mm per day 0.4 0.3 0.2 0.44 hatchery wild % Body weight per day 1.5 1.0 1.7 Hatchery Wild 0.1 0.21 0.5 0 0.0 0.4
Discussion Differences b/t hatchery and wild Domestication effects (raceways, pellets) High movements Non-complex habitat selection Slow growth Equals predation Led us to study acclimating pelletreared fish to the wild
Post-Stocking Survival of Naïve vs. Conditioned Hatchery-Reared Largemouth Bass
Can post-stocking survival be increased through conditioning? Condition one batch of fish to the natural photoperiod, habitat, predators, and forage in an earthen pond Compare survival of conditioned fish to those straight from the raceway
Conditioning ½ acre conditioning pond: 10 days Predators: bass and bowfin Forage: mosq fish Cover: 10 brush piles
Research Ponds Four 1-acre ponds Community structure stocked 10 brush piles (standardized habitat) Ponds stocked with both conditioned and naïve fish Trial run 30 days and harvested
80 70 60 Survival Pond 21 Pond 22 Pond 28 Pond 29 Mean for 4 ponds combined Percent Survival 50 40 30 20 naive conditioned 10 0 P = 0.001
Conditioned fish Mean Total Length (mm) 120 110 100 90 Pond 21 Pond 22 Pond 28 Pond 29 Mean for 4 ponds combined naive conditioned naive 80 P < 0.01
Discussion Nearly doubled survival in research ponds Faster growth post stocking Improved foraging and predator avoidance (tank experiments) Translate to natural lakes? Acclimating production #s?
Objectives Small lakes stocking study 1. Survival of phase II bass with high replicates Stock 11 lakes spring 2012 (50/acre) All fish tagged (MWT) Evaluation spring 2013 (age-1) and 2014 (recruit to fishery) with pop est. 2. Compare survival b/t raceway fish and those conditioned in predator free nets Stock spring of 2013 Condition in-lake for 5 days Evaluate spring 2014
Anticipated results Survival information for managers to make informed stocking decisions Determine survival differences by in-lake conditioning Will survival increase and improve stocking success
Is Stocking the Answer??? What do we recommend based on data?
Ocklawaha Chain of Lakes bass update Long Term Monitoring Standardized beginning 2007 Spring electrofishing Catch rates Size structure Relative weights Angler surveys Lake Harris Lake Griffin Exploitation Future sampling
Monitoring bass populations Small lakes Mark-recapture population estimates Large lakes Relative abundance Catch per unit of effort
Monitoring bass populations 12 Relative abundance (Catch rate) 10 8 6 4 2 0 0 2000 4000 6000 8000 10000 12000 Abundance
Relative abundance Catch rates
Spring bass electrofishing 2012 60 50 Bass catch per 15 minute transect 40 30 20 10 > 9" < 9" 0 Eustis Harris Dora Griffin Beauclair Apopka
50 45 Catch rates 2007-12 40 Catch per 15 minute transect 35 30 25 20 15 Apopka Griffin Harris Dora Eustis Beauclair 10 5 0 2007 2008 2009 2010 2011 2012
35 30 Griffin Catch per 15 minute transect 25 20 15 10 5 0 2007 2008 2009 2010 2011 2012
30 25 Griffin 3500 3000 Catch per transect 20 15 10 5 Griffin Vegetation 2500 2000 1500 1000 500 Acres of vegetation 0 2007 2008 2009 2010 2011 2012 0
30 25 Griffin 0.7 0.6 Catch per 15 minute transect 20 15 10 Catch rates Success 0.5 0.4 0.3 0.2 Catch per hour 5 0.1 0 2007 2008 2009 2010 2011 2012 0
35 30 Beauclair Catch per 15 minute transect 25 20 15 10 5 0 2007 2008 2009 2010 2011 2012
35 30 Apopka Catch per 15 minute transect 25 20 15 10 5 0 2007 2008 2009 2010 2011 2012
35 30 Harris Catch per 15 minute transect 25 20 15 10 5 0 2007 2008 2009 2010 2011 2012
35 30 Dora Catch per 15 minute transect 25 20 15 10 5 0 2007 2008 2009 2010 2011 2012
55 Eustis 45 Catch per 15 minute transect 35 25 15 5-5 2007 2008 2009 2010 2011 2012
Catch of Age-1 Bass 15 13 Catch per 15 minute transect 11 9 7 5 3 Dora Eustis Apopka Harris Griffin Beauclair 1-1 2007 2008 2009 2010 2011 2012
Dora and Apopka Age 1 15 13 Catch per 15 minute transect 11 9 7 5 3 Dora Apopka 1-1 2007 2008 2009 2010 2011 2012
Griffin and Harris Age 1 15 13 Catch per 15 minute transect 11 9 7 5 3 Harris Griffin 1-1 2007 2008 2009 2010 2011 2012
20 Eustis Age 1 18 16 Catch per 15 minute transect 14 12 10 8 6 4 2 0 2007 2008 2009 2010 2011 2012
Percent frequency Percent frequency 10% 9% 8% 7% 6% 5% 4% 3% 2% 1% 0% 10% 9% 8% 7% 6% 5% 4% 3% 2% 1% 0% Griffin 2007 Age-1 bass 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Griffin 2012 Age-1 bass 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Inch group
Percent frequency Percent frequency 10% 9% 8% 7% 6% 5% 4% 3% 2% 1% 0% 10% 9% 8% 7% 6% 5% 4% 3% 2% 1% 0% Eustis 2007 Age-1 bass 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Eustis 2012 Age-1 bass 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Inch group
10% 9% Dora 2012 8% 7% 6% 5% 4% 3% UF Wild 2% 1% 0% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
105 Condition of Bass (Relative Weights) 100 Eustis Relative Weight 95 90 Dora Beauclair Harris Griffin Apopka State average 85 80 2007 2008 2009 2010 2011 2012
30 25 Griffin Catch rate Wr 105 103 101 20 99 Catch per transect 15 97 95 93 Condition 10 91 5 89 87 0 2007 2008 2009 2010 2011 2012 85
Lake Harris Creel 2011-12 Largemouth bass 2007-08 2011-12 Hours 43,872 50,407 Catch 15,435 26,153 Success 0.32 0.53 Fisheries managers target 0.25 as goal for quality fishery Anglers: 87% fish from boat 78% resident 32% bass tournament
Griffin Exploitation 300 fish tagged in lake and canals high rewards Year 1 Caught 20% (60/300) Removed - 2.7% (8/300) Fishing mortality of little concern for population Recruits and habitat! Number 30 25 20 15 10 5 0 Griffin Tag Returns Not Caught Fish Caught 350 390 430 470 510 550 590 630
Are we there yet? #1 freshwater fisheries problem in FL Habitat degradation Ock. Chain We ve seen improvements not recovered Long way to go Where are those improvements - learn from them replicate Submersed Veg Water fluctuations
Sampling for 2012-13 Fall community sampling Spring bass sampling Fall trawling for crappie Angler surveys Griffin evaluate crappie rule change Eustis Long term monitoring Apopka Use study as baseline for restoration Study to assess the effects of fishing nesting bass Will include Lake Eustis